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As micropyle on is referred to seed plants an opening at the tip of the ovule and in the eggs of certain insects an opening in the egg .


In seed plants, the integument (s) grow around the nucellus , but do not enclose it, but leave an opening free through which the pollen tube can penetrate.

In the area of ​​these micropyls, cycads and some coniferous plants excrete a drop of liquid that draws the pollen capillary to the embryo sac as it dries up and z. B. should "encourage" germination through a high sugar concentration.


The micropyle, which is also referred to here as a micropylar cup, is a bulge in the outer egg shell (exochorion) of some insects , e.g. B. the butterflies and the ghosts into which the sperm can penetrate. This is located either on the top or on the back of the egg. In butterflies, it forms a rosette-shaped structure. In the case of the ghosts, it is surrounded by a micropylar plate, which is usually shaped specifically for the species.


Different types of micropylene occur in the eggs of different fish species.

Individual evidence

  1. ^ Yvette W. Kunz: Developmental Biology of Teleost Fishes. Springer, 2004, ISBN 1-4020-2995-0 , pp. 109–120, limited preview in the Google book search.